-6.48% is the change from 664 to 621
Calculation steps:
[( 621 - 664 ) ÷ 664] x 100 = -6.48%
Formula
Percentage change = [(621 - 664) / 664] x 100
Subtract the new number by the original number
621 - 664 = -43
-43 ÷ 664 = -0.06475903614457831
-0.06475903614457831 x 100 = -6.48%